Practical guide
How to Estimate Roof Tiles for a House
Roof tiles should be estimated from the sloping roof surface, not only the building floor area. The exact coverage depends on the tile profile, pitch, headlap and manufacturer installation requirements.
Fact checked and updated 13 September 2026
Use the true roof area
Measure or obtain the sloping area for every roof plane. Include additions, porches and garages where they use the same product. Complex hips, valleys and dormers usually increase cuts and waste.
Use manufacturer coverage
Enter the tiles per square metre stated for the chosen product and roof pitch. Do not copy a rate from a different profile. Ridge, hip and verge tiles are separate accessories and should be measured independently.
Round to purchasing units
Add a practical breakage and cutting allowance, then round up to full packs or pallets. Keep a small number of matching tiles for future repairs if the supplier recommends it.
Use the related calculators
Apply the explanation above with your own figures. Open a calculator below, check every input and review the result assumptions before making a decision.
Official source checked
This guide was checked against South African Bureau of Standards. Rules, rates and institutional requirements can change, so confirm time-sensitive information at the official source.